Electrosyntheses of 3-acetyl- and 3-methoxycarbonyl-2,5-dimethoxy-2,5-dihydrofuranes

Electrochemical methoxylation of furane derivatives has been used to synthetize 3-acetyl-2,5-dimethoxy-2,5-dihydrofurane ( I ) and methyl 2,5-dimethoxy-2,5-dihydro-3-furoate ( II ). Addition reaction of methanol with the ester II gave rise to methyl 2,4,5-trimethoxytetrahydro-3-furoates IVa-IVc , which were separated and identified by their 1 H NMR spectra. Using the same method, we identified isomeric 3-hydroxymethyl-2,4,5-trimethoxytetrahydrofuranes Va-Vc , formed by reduction of the ester II with a hydride, and methyl 2,5-dimethoxytetrahydro-3-furoates VIa-VIc , formed by hydrogenation of II on Pd.